PURPOSE: To prevent the adhesion of fine silicon particles, dust, etc., to the surface of a semiconductor element during die bonding so as to improve the quality of a semiconductor device by sticking a heat-shrinkable protective sheet to the surface of a wafer and removing the sheet by heating after dicing and die bonding.

CONSTITUTION: A semiconductor element is manufactured in such a way that a wafer 1 on which semiconductor elements are formed is diced into chips 2 and each chip 2 is die-bonded to each package. At the time of dicing the wafer 1, a heat-shrinkable protective sheet 3 is stuck to the surface of the wafer 1 and the wafer 1 is diced together with the sheet 3. Then, after die- bonding each chip with the sheet 3 to each package, the sheet 3 is removed from the surface of the chip 2 by heating the chip 2. When, for example, the chip 3 is heated for 30 minutes at 80°C in dry air, the sheet 3 shrinks and curles and, finally, comes off from the surface of the chip 2.